A study on the effect of stress state on damage evolution in hot deformation of free cutting steels using double notched bars
File(s)Kardoulaki et al Manuscript (R2).docx (4.45 MB)
Accepted version
Author(s)
Kardoulaki, E
Lin, J
Balint, D
Farrugia, D
Type
Journal Article
Abstract
The effect of stress state on the initiation of damage for leaded free cutting steel has been investigated under hot rolling conditions. Double notched (DN) circumferential tension samples were designed and used to simulate damage development at different stress states and deformation conditions using a Gleeble (3800) thermal-mechanical testing system. Two DN sample geometries with varying notch profiles were used to account for different states of stress. To simulate the conditions of hot rolling the samples were tested at high temperatures (900–1200 °C) and moderate strain rates (0.1–1 s−1). After testing to failure, which normally occurs at one notch of the specimen, the unfailed notch of each sample was sectioned to examine the sites where damage occurs since the material has been captured in a state very close to failure. Two of the cases examined have shown definitive damage paths occurring from ‘outside–in’ for a sharp notch deformed at T = 900 °C and from ‘inside–out’ for a blunt notch tested at T = 1200 °C for the same strain rate of 0.1 s−1. The experimental results of the failure initiation sites were compared with computed values of the stress fields around the notch profiles, obtained from FE analysis using a set of viscoplastic constitutive equations calibrated for free cutting steel. The temperature profiles from high temperature mechanical testing were used in the FE calculations of the stress state.
Date Issued
2016-06-27
Date Acceptance
2016-04-16
Citation
Philosophical Magazine, 2016, 96 (21), pp.2176-2203
ISSN
1478-6435
Publisher
Taylor and Francis
Start Page
2176
End Page
2203
Journal / Book Title
Philosophical Magazine
Volume
96
Issue
21
Copyright Statement
© © 2016 Informa UK Limited, trading as Taylor & Francis Group. This is an Author's Accepted Manuscript of an article published in the Philosophical Magazine, complete citation information for the final version of the article is available online at: http://www.tandfonline.com/10.1080/14786435.2016.1181280
Sponsor
Tata Steel UK Ltd
Grant Number
VAT GB 238 7122 60 000
Subjects
Science & Technology
Technology
Physical Sciences
Materials Science, Multidisciplinary
Mechanics
Metallurgy & Metallurgical Engineering
Physics, Applied
Physics, Condensed Matter
Materials Science
Physics
Double notched bars
stress state
hot forming
damage evolution
ductile fracture
free cutting steel
HIGH-STRENGTH STEELS
DUCTILE FAILURE
CREEP-RUPTURE
FRACTURE CHARACTERISTICS
ROLLING CONDITIONS
TENSILE TESTS
STRAIN-RATE
TRIAXIALITY
GROWTH
TEMPERATURE
Materials
01 Mathematical Sciences
02 Physical Sciences
09 Engineering
Publication Status
Published
Date Publish Online
2016-06-27